fuel filter

[kslle]

ok i had a brain freeze... stainless steel filter, solid end goes to motor side, open to fuel cell right?

[jwracer11]

ok i had a brain freeze... stainless steel filter, solid end goes to motor side, open to fuel cell right?

No, it's the opposite. Solid end and spring go towards fuel cell and open end to the motor.

[BlackMagic]

According to Willy's the solid end and spring need to be on engine side. They are pretty stern on this. Can't remember why they prefer it this way though.

[Wheelman33]

👆 Was told the same thing.

[Lizardracing]

I see this listed improper quite often in my opinion.

Spring on the engine side is the correct way for most of inline cartridge style filters.
Take a look at the end of the filter and note the end with the hole in the center. Fuel is supposed to goes into the center hole and then is filtered outward and then out the engine side of the canister. If the filter gets plugged up, fuel will push the filter against the spring allowing the fuel to bypass around the filter. I do mine like this on a modified running gas.

If the spring is put on the wrong side and the hole facing the output side then fuel will go outside inward and out the small hole and doesn't provide a bypass if things get plugged up. This is the way I see it listed all the time in instructions as the correct way. If you put the spring on the wrong side and the filter in the wrong way then fuel will not flow at all as it cannot get past the endcap and the output side of the canister.

[Matt49]

Lizard, the way you describe it and the way it is in your picture are opposite. FWIW I think the picture is correct. Outside in is how must filters work for several reasons. Not the least of which is that you can see how good of a job it was doing when you replace it.
I'm not sure I understand the bypass ideo. We don't have fuel pumps in the fuel cell so I don't understand how that would even work. And if there is enough garbage in your fuel to completely clog a fuel filter, I would think the last thing you want is to bypass it. Whatever clogged the filter is surely going to plug up the carb.

[Racer96m]

I see Willys saying to turn the filter around. Its not the way it was designed to work. This type of filter comes from aviation, my chosen field for the last 30 yrs. Aviation runs the Stainless cartridge filters on everything. They were designed to be removed and inspected and cleaned if need be. If the fuel went from the inside out, you couldnt inspect it very well and or clean it and re use it. You can run it this way if you want to use the more restrictive disposable paper filters, but if you run the stainless reusable filter it needs to flow from the outside in, so it can be properly cleaned and inspected. And the spring wasnt put in there as a Bypass. Thats a big spring, and would take more psi than you have to compress it. As long as the spring is always on the closed end it will always work, but if you run a stainless filter from the inside out, dont switch back to the correct outside in or you will send all the contaminates you cant clean out right into your carb. Just my .02

Dave.

[50j]

Simply put, closed end and spring to fuel cell. Open end to fuel pump.

[MM90]

Fuel flows from outside in, not inside out through the fuel filter element.

[Racer96m]

This is the post from Willys Carb.

****Technical Bulletin for ALL RACERS****
Any racer using a canister style fuel filters needs to know the directions enclosed with the filter is INCORRECT!
For a number of years we have all installed the filter element incorrectly which in turn has reduced fuel pressure, reduced power, torque, caused engine failures among numerous other issues. This is especially true with any car running a return line and now our "Super Bowl" system.
As you see in the photo, your spring that is inside the filter canister should ALWAYS be placed on the engine end and the hole that is in the end of the element should be on the fuel cell end.
For the past several years Willy' has tried reaching out to manufacturers of these fuel filters to have them correct their instructions and to educate them however, this is a common problem we see or hear about daily.
We hope this tech bulletin is helpful for you and your team. We feel that everyone needs to be educated on this issue and ask for you to share this topic on your page as well.


I personally disagree with this, for the reasons I stated in previous post. I think whats driving this is the fuel pressure requirements for there SuperBowl Carb. So I guess if you run one of those, do what they tell you,use paper filters and change them often, or get even better flow and pressure with a stainless filter and throw it away like a paper one along with your money!

Dave

[rakracing]

i'm with matt on this one .solid end toward fuel cell ,hole toward engine, if installed the other way the surface area to clog if much smaller 26 years of racing and 28 years as a plumber, filter never goes that way.

[stock car driver]

I cant believe something even as simple as this can be muddied up...

I can think back to a whole lot of dingy posts now I wonder if any of them were the brains at willys, lol.

[cjsracing]

I had a friend who had it installed like Willy's is saying and his car wouldn't run, I told him to put the spring and solid end towards the fuel cell and it then ran like it should.

[brad hibbard]

I think we are missing some of the Willy's information-----
I am not a customer of Willys but respect there position in the industry with innovative and quality products
there is missing information here because when using a traditional style canister fuel filter if it is simply turned around backwards with NO modifications---the fuel pump will draw the filter toward the spring-- completely closing off fuel flow
I have fixed this condition liteally hundreds of times when a competitor tells me his car is laying down real bad at mid straightaway----I ask if they recently serviced their fuel filter----the answer is usually yes and then we proceed to find it in with the open end (hole) toward the fuel cell and spring toward the pump (engine)

we switch it around and problem fixed

there may be a modification or set up change to allow proper fuel flow to go from inside out but then the filter would be only disposable not servicable----which is not necessarily bad

on another note
IF you were able to modify this style filter design to flow inside out and the user accepts that it is a replacement cartridge it would most likely be a better "filtering" system
the traditional system does permit debris to bypass especially on a rough race track

Brad Hibbard
www.race-1.com

[Lizardracing]

I guess the debate goes on.
I'd rather bypass the filter than blow up a motor going lean. I'd rather have a smaller particulate matter capabilities and throwing away the cartridge then cleaning it. I'd rather increase the square filtering area to make up the difference in flow direction. I'd rather follow the directions of an expressed or implied warranty over any of the above rantings or my own opinion haha!


I wish someone would post some flow numbers on each direction.

Here's another question...Why a spring at all? Why not a spacer or some other design change unless the spring actuation is part of the overall design function? I suppose the key question we need to answer is "What is the function of the spring?". The answer to that shall be the answer of which end it goes on.

[50j]

I'd think the filter manufacturers would know how it should be installed. A simple fuel pressure gauge would let you know if there's a problem with fuel flow somewhere.

[zeroracing]

The spring serves to keep pressure on the closed end of the filter, keeping the open end with the small seal against the engine side of the filter housing. They use a spring to keep this pressure as well as work as a spacer. The reason they use a spring over a machines spacer is it auto adjust to manufacturing differences in suppliers and is cheap to buy. Why machine a spacer when a .50 spring will do the same job.

If your getting enough debris in your filter to plug it you either need to clean it out more often, screen your fuel when you fill it up or clean out the cell. Their is no reason you should plug one up. If you have that much trash going through it will plug up the pump or carb if it goes on anyways.

The final note about fuel flow, which one flows more? What does it matter a gas powered open late model gets more than enough fuel from the filter installed correctly, heck an open car on methanol does also. If your cutting it close on your fuel requirements then you need to look at less pressure head loss like hard polished lines, larger radius fittings, special inlet device... All of which is not needed.

I cannot find a reason why you would want to run it closed side to the motor, been there and seen guys have issues with them with spring on either end, closed in toward motor just does not make sense. Now it could work, not right but could work if you put a very stiff spring in it, 3-4 x as stiff as the standard and kept that open end pinned against the wall.

If you use the standard spring and plan is once it plugs it will compress the spring and let fuel bypass... Probably the resistance of the filter itself is enough to do this and your bypassing most of the time anways.

[50j]

Exactly how I see it. Installed like the manufacturers recommend with the closed end and spring toward the cell and the open end toward the engine, I have never had a single issue with it. That includes methanol, and of course a stainless element. I've seen plenty of problems with them put together other various ways. I hope the manufacturers aren't in a hurry to be edjumicated because they work fine.

[cheaterleaddog]

These filters were originally designed for gas pump filters at gas station(they are still used on the filler hose today not to be confused with break away valve for the person who drives off with hose in the car still.) and the spring was to allow to bypass a plugged filter just like the OEM spring and filter inside a Rochester carb. For racing applications the spring and closed end of the filter goes towards fuel cell.

[Lizardracing]

Now that's making sense. It's embarrassing to drive away with the hose still in the car. Now why can't someone design a way to fill up without stopping like the airplanes do? Wouldn't that add something to NASCAR? The "No Stop Pit Stop?"